Various studies indicate that an implanted lead may fail for one or more reasons. For example, a study by Dorwarth et al., “Transvenous defibrillation leads: high incidence of failure during long-term follow-up”, J Cardiovasc Electrophysiol., 14(1):38-43 (2003), found that a majority of lead-related sensing failures were associated with insulation defects that occurred late after ICD placement (6.0+/−1.8 years after implant). Dorwarth et al. recognized that “automated device control features with patient alert function integrated into new devices may contribute to early detection of lead failure”. Thus, a need exists for techniques to detect lead failure.
To date such techniques typically rely heavily on impedance measurement. For example, excessive lead impedance may indicate loss of a connection due to a conductor fracture and low lead impedance may indicate a short circuit or alternative conduction path due to an insulation failure. To date, impedance techniques are typically implemented by a care provider during follow-up or perhaps on a programmed, periodic basis (e.g., time schedule). Such techniques may not uncover lead issues in a timely manner. As described herein, various exemplary mechanisms are presented that can improve timeliness of detection and/or improve timeliness of adjustments to therapy in response to a lead issue. Other advantages are also discussed herein.